Scanner module and image scanning apparatus employing the same

ABSTRACT

Disclosed are a scanner module and an image scanning apparatus employing the same. The scanner module includes a light source generating light to be irradiated onto an object and a light guide member extending in correspondence with a width of the object. The light guide member has a reflective surface defined by a plurality of reflective grooves, some of which arranged to be non-parallel with other ones. Light is effectively diffused and/or scattered in the width direction of the light guide member by the reflective grooves, allowing a uniform light distribution across the scanning width.

This application claims the benefit of Korean Patent Application No.10-2007-0069502 filed on Jul. 11, 2007 and Korean Patent Application No.10-2008-0001494 filed on Jan. 4, 2008, the disclosures of both of whichare incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image scanning apparatus. Moreparticularly, the present invention relates to a scanner module using alight emitting diode as a light source and an image scanning apparatusemploying the same.

2. Description of the Related Art

A scanner module may be employed in an image scanning apparatus, e.g.,of a scanner, a copy machine, a facsimile, a multi-functional peripheraldevice, or the like. The scanner module may be placed, e.g., underneatha document window or platen onto which an original document to bescanned is loaded, and converts the image information read from thedocument into an electric signal.

A scanner module may include, e.g., a light source generating light, animage sensor that produces electrical signal based on the lightreflected from the object to be read. A scanner module may also includea reflection mirror and a condenser lens, which may be aligned in anoptical path formed between the light source and the image sensor. Alinear light source, such as, e.g., a CCFL (cold cathode fluorescentlamp) or a xenon lamp has been used as the light source in some legacyscanner modules.

However, a CCFL may require a long initial start-up time, which mayresult in longer time to perform an initial scanning operation. Inaddition, since the CCFL may contain mercury (Hg), which may haveadverse impact on the environment. Further, gas activation rate may belower, possibly degrading image quality, at lower temperatures. A xenonlamp may generate high-temperature heat, which may degrade the imagequality, and can be expensive, resulting in the price competitiveness ofthe scanner module to suffer.

Recently, there have been suggestions for the use of a point lightsource, such as a light emitting diode, along with a light guide toserve the role of a linear light source by allowing the light from thepoint light source to be diffused and/or directed along the scanningwidth, e.g., across the width of the document or object to be scanned.

As shown in FIG. 1, a light guide member 2 employed in a scanning modulemay have a predetermined width in the image scan direction and apredetermined length in the sub-scan direction (i.e., directionsubstantially perpendicular to the image scan direction). The lightguide member 2 may also include an exit surface 2 a facing the object tobe scanned, a reflective surface 2 b formed on the opposite end of theexit surface 2 a to reflect and diffuse the light generated from a lightsource 1, and guide surfaces 2 c formed on both sides of the light guidemember 2 to connect the exit surface 2 a to the reflective surface 2 b.The guide surfaces 2 c may be inclined relative to the reflectivesurface 2 b such that the light reflected from the reflective surface 2b can be directed toward the exit surface 2 a of the light guide member2.

As shown in FIG. 2, the reflective surface 2 b of the light guide member2 may include a plurality of reflective grooves 2 d, which extendwidthwise, parallel to each other, along the light guide member 2, sothat the light generated from the light source 1 may be reflected anddiffused by the reflective surface 2 b, and then may be guided towardthe exit surface 2 a of the light guide member 2. FIG. 3 shows anexample of a distribution of light, which is irradiated onto the surfaceof a document to be scanned from the light guide member 2, across theimage scan direction. As illustrated in FIG. 3, unfortunately, when apoint light source and light guide structures shown in FIGS. 1 and 2result in the light distribution to be non-uniform, making it difficultto accurately read the object being scanned.

SUMMARY OF THE INVENTION

Accordingly, it is an aspect of the present invention to provide ascanner module having a light guide member capable of formingsubstantially uniform light distribution across the scanning width andan image scanning apparatus employing the same.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be apparentfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofthe embodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a sectional view of a light guide member employed in aconventional image scanning apparatus;

FIG. 2 is a schematic plan view showing a reflective surface of a lightguide member employed in a conventional image scanning apparatus;

FIG. 3 is a graph showing light distribution along the width of a lightguide member in the scanning direction when light is radiated from bothlongitudinal ends of the light guide member employed in a conventionalimage scanning apparatus;

FIG. 4 is a schematic view showing a scanner module employed in an imagescanning apparatus according to an embodiment of the present invention;

FIG. 5 is a schematic view showing an illumination device employed in animage scanning apparatus according to an embodiment of the presentinvention;

FIG. 6 is a perspective view showing an illumination device employed inan image scanning apparatus according to an embodiment of the presentinvention;

FIG. 7 is a sectional view of the illumination shown in FIG. 6;

FIG. 8 is a graph showing light distribution on the surface of amanuscript in the width direction of the light guide member employed inan image scanning apparatus according to an embodiment of the presentinvention;

FIG. 9 is a sectional view of a reflective surface of a light guidemember employed in an image scanning apparatus according to anembodiment of the present invention;

FIG. 10 is a schematic plan view of a reflective surface of a lightguide member employed in an image scanning apparatus according to anembodiment of the present invention;

FIG. 11 is a graph showing light distribution on the surface of amanuscript in the width direction of the light guide member employed inan image scanning apparatus according to an embodiment of the presentinvention;

FIG. 12 is a sectional view showing a light guide member according to anembodiment of the present invention;

FIG. 13 is a block diagram of an image scanning apparatus according toan embodiment of the present invention;

FIG. 14 is a perspective view showing an illumination device employed inan image scanning apparatus according to an embodiment of the presentinvention;

FIG. 15 is an enlarged perspective view of “A” shown in FIG. 14;

FIG. 16 is a sectional view of a light guide member according to anembodiment of the present invention;

FIG. 17 is a schematic view of an illumination device employed in animage scanning apparatus according to an embodiment of the presentinvention;

FIG. 18 is a sectional view of an illumination device employed in animage scanning apparatus according to an embodiment of the presentinvention;

FIG. 19 is a plan view of a light guide member employed in an imagescanning apparatus according to an embodiment of the present invention;

FIG. 20 is a plan view of a light guide member employed in an imagescanning apparatus according to an embodiment of the present invention;and

FIG. 21 is a plan view of a light guide member employed in an imagescanning apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elements.

FIG. 4 is a schematic view illustrating an optical arrangement of ascanner module 10 according to an embodiment. Referring to FIG. 4, ascanner module 10 according to this embodiment may include anillumination device 100 that irradiates light onto an object 55 placedon the manuscript board 51, an image sensor 130, which receives thelight reflected from the object 55, and which converts the light intoelectric signals, a plurality of reflection mirrors 140, which directthe light reflected from the object 55 toward the image sensor 130, anda focus lens 120 arranged in front of the image sensor 130 in theoptical path such that the light can be focused on the image sensor 130.

Among the above elements of the scanner module 10, the image sensor 130reads image information of the object 55 based on the light that isfocused on the image sensor 130 through the focus lens 120. The imagesensor 130 can provided with various arrangement of sensing elementsaccording to the desired image scanning application. For example, theimage sensor 130 may be arranged in a single row or in a plurality ofrows of sensor elements for color image scanning of red/green/blue orred/green/blue/white-black.

According to an embodiment, a plurality of reflecting mirrors 140 may beprovided between the object 55 and the focus lens 120. The plurality ofreflecting mirrors 140 reflect light from the object 55, to change thedirection in which the light travels, thereby allowing a predeterminedoptical path in a limited space. While, for illustrative purposes, fourreflecting mirrors 140 are shown in FIG. 4, one skilled in the art willappreciate that the number of reflecting mirrors 140 can be variedwithout departing from the scope of the disclosure.

The scanner module 10 may further include a light aperture or window 150to regulate the light traveling toward the image sensor 130. To thisend, the light window 150 is disposed between the illumination device100 and the reflection mirrors 140 to prevent undesired light fromreaching the image sensor 130.

FIG. 5 is a schematic view illustrating an optical arrangement of anilluminator of a scanner module according to an embodiment, and FIG. 6is a perspective view of the illuminator of FIG. 5.

Referring to FIGS. 5 and 6, the illuminator 100 illuminates the documentor manuscript board 51 by sending light along a sub-scanning direction(see the Y-direction in FIG. 8). This sub-scanning direction issubstantially perpendicular to an image scanning direction (X-direction)of the scanner module. The illuminator may include a light source 200emitting light, and a light guide unit 210 extending lengthwise in thesub-scanning direction Y and facing the manuscript board 51.

The light guide unit 210 guides the light toward the object 55 bydiffusing the light from the light source 200. The light guide unit 210includes a pair of light guide members 210A and 210B facing themanuscript board 51, and each extend longitudinally along the sub-scandirection (Y-direction as shown in FIG. 6) defining the lengths of thelight guide units while along the image scan direction (X-direction) thewidths of the light guide units 210 are defined.

According to an embodiment, the light source 200 may include lightemitting diodes capable of emitting light having a wavelength band ofthree primary colors, namely, red, green and blue. The light emittingdiodes may be semiconductor devices, an may be capable of generating asufficient amount of light within a relatively short period of time incomparison to a CCFL or the xenon lamp. Thus, the start-up time of thescanner module 10 can be shortened and power consumption can be reduced.For example, when a light emitting diode is used as the light sourceaccording to an embodiment of the present invention, since the lightemitting diode, which is a semiconductor device, may achieve the peakamount of light output within in a short period of time, e.g., 1 μs, thestart-up time of the light source may be shorter in comparison with thata light source utilizing a CCFL which may require the start-up time inexcess of, e.g., 30 seconds.

Moreover, a light emitting diode may also be advantageous as a lightsource over a CCFL as unlike a CCFL that is driven at high voltage,e.g., at several hundreds to thousands of voltages, the semiconductorlight source can be driven at a low voltage, obviating the need for theuse of inverters used for voltage boosting and AC generation. Thus, themanufacturing cost can be reduced and space utilization can be improved.Also, since the inverters can be omitted, power consumption can bereduced.

Further, while in the case of a CCFL, the amount of light may be reducedat low temperature, the semiconductor light source according to anembodiment of the present invention may be capable of relatively stablelight output over wider temperature range. In addition, a semiconductorlight source may also reduce the amount of the electromagnetic waves,which may be a source of noise for internal circuits. Further, thesemiconductor light source of an embodiment of the present invention maybe more durable as compared with the CCFL which is made from thin glassmaterial.

Furthermore, the light emitting diodes may have longer operating life,e.g. of about hundred thousand hours, as compared to a CCFL. Inaddition, the light emitting diodes can be fabricated without mercury(Hg) that may present environmental concern.

Although, in the embodiment described above, light emitting diodescapable of emitting light having a wavelength band of three primarycolors are used as the light source 200, the scope of the application ofthe present invention is not so limited. For instance, a white lightemitting diode coated with fluorescent material to generate blue coloror an ultraviolet ray to generate a white color, can also be used as thelight source 200. Further, various types of point light sources otherthan a light emitting diode can alternatively be used as the lightsource 200.

The light guide members 210A and 210B convert the optical path of lightirradiated from the light source 200 such that the light can beirradiated onto at least two regions A₁ and A₂. The light guide members210A and 210B are spaced apart from each other in the image scandirection. For the purpose of convenience, the light guide member 210Aprovided on one side of the image scan direction will be referred to asthe first light guide member and the light guide member 210B provided onthe other side of the image scan direction will be referred to as thesecond light guide member. The centers C₁ and C₂ of the two regions A₁and A₂ are spaced apart from each other in the image scan direction X bya distance d. Therefore, the light can be illuminated onto the center Cof the object 55 placed on the manuscript board 51 as well as apredetermine region of the object 55 which deviates from the center C ofthe object 55.

According to the embodiment shown in FIGS. 5 and 6, the illuminationdevice 100 can illuminate the light onto the first and second regions A₁and A₂ and a pair of light guide members 210A and 210B are provided toguide the light onto the first and second regions A₁ and A₂. Inaddition, the illumination device 100 may further include a holder 230for guiding the installation position of the light guide members 210Aand 210B when the light guide members 210A and 210B are installed in theoptical path.

The light guide members 210A and 210B may have elongated shapesextending in the sub-scan direction Y, and may include transparentmaterials, such as, e.g., PMMA (polymethyl methacrylate). Each of thelight guide members 210A and 210B may have an incident surface 211, aguide surface 213, a reflective surface 215 and an exit surface 217.

The light from the light source 200 is incident onto the incidentsurface 211. The incident surface 211 is formed on at least onelongitudinal end portion of the light guide members 210A and 210B andthe light source 200 faces the incident surface 211.

For example, FIG. 7 shows incident surfaces 211 that are formed on bothlongitudinal end portions of the light guide members 210A and 210B. Alsoaccording to the embodiment shown in FIG. 7, the light sources 200 areprovided to correspond to the incident surfaces 211 formed on bothlongitudinal end portions of the light guide members 210A and 210B toirradiate light to the incident surfaces 211, thereby increasing theamount of light in the illuminator 100.

The light guide members 210A and 210B, when installed in the holder 230,are slantingly arranged such that the light reflected from the object 55does not interfere with the light guide members 210A and 210B. That is,as shown in FIG. 5, the central line of light that is output from thelight guide members 210A and 210B is inclined relative to a centraloptical axis Z of the light.

FIG. 8 is a graph showing light distribution on a surface of a documentto be scanned in the width direction of the light guide members 210A and210B when the light source and the light guide members 210A and 210B arearranged as shown in FIG. 5.

Referring to FIG. 8, reference numeral 251 represents a lightdistribution curve on the surface of the manuscript placed on themanuscript board 51 when the light is output from the first light guidemember 210A, and reference numeral 253 represents a curve showing lightdistribution on the manuscript board 51 when the light is output fromthe second light guide member 210B. In addition, reference numeral 255represents a curve showing the total light distribution on themanuscript board 51.

Referring again to FIG. 5, when the light sources 200 and the lightguide members 210A and 210B are arranged as shown, the amount of lightirradiated onto the manuscript board 51 is maximized at the center C₁ ofthe first region A₁ and at the center C₂ of the second region A₂. Aspreviously mentioned, the center C₁ of the first region A₁ is spacedapart from the center C₂ of the second region A₂ by the distance d.Referring to the curve 255 that is the sum of the curves 251 and 253,the amount of light irradiated onto the first and second regions A₁ andA₂ is substantially constant in the region between the center C₁ of thefirst region A₁ and the center C₂ of the second region A₂.

The illumination device 100 having the above structure can illuminatelight over a relatively large region of the manuscript as compared withthe conventional illumination device. Thus, the illumination device 100can be employed in the scanner module 10 capable of performing colorscanning operation, and the optical elements constituting the scannermodule 10 may have a relatively large assembling tolerance, so thatproductivity of the scanner module 10 can be improved.

The scanner module 10 according to an embodiment employs theillumination device 100 capable of illuminating light over therelatively large region of the manuscript, so that the output value ofthe image sensor 130 may remain uniform despite possible deviations inpositioning of the reflection mirrors 140 and the focus lens 120 duringassembly of the illumination device 100.

The exit surface 217 faces the manuscript board 51. The light that isdiffused and reflected by the reflective surface 215 and the guidesurface 213 may be output through the exit surface 217. The exit surface217 may function as a condenser lens that focuses the light on themanuscript board 51, so that light illuminated in the first region A₁may have a Gaussian distribution. According to the present embodiment,as shown in FIG. 5, the exit surface 217 is provided as a convex lenshaving an arc-shape section with a predetermined curvature.

The reflective surface 215 is disposed in opposition to the exit surface217 so as to diffuse and reflect the light incident through the incidentsurface 211, thereby allowing the light to be uniformly output throughthe entire surface of the exit surface 217. To this end, the light ispreferably subject to scattered reflection over the entire area of thereflective surface 215.

According to an embodiment, and as shown in FIG. 9, the reflectivesurface 215 may be formed with a plurality of reflective grooves 215 aand 215 b so that the light from the light source 200 is subject to ascattered reflection. According to an embodiment, the reflective grooves215 a and 215 b may have triangular sectional shapes to guide the lightreceived from the light source 200 through the incident surface 211 atlongitudinal end portions of the light guide members 210A and 210Btoward the exit surface 217 of the light guide members 210A and 210B.The amount of light reflected toward the exit surface 217 of the lightguide members 210A and 210B by the reflective grooves 215 a and 215 bmay increase proportionally to the height H of the triangular section ofthe reflective grooves 215 a and 215 b and to the inclination angle θ1of the lateral side of the triangular section. Therefore, the amount oflight irradiated from the light guide members 210A and 210B can beadjusted by properly adjusting the height H and the inclination angle θ1of the triangular section of the reflective grooves 215 a and 215 b.

Although the above embodiment has been described to be provided with thereflective grooves 215 a and 215 b formed in the reflective surface 215having the triangular cross-section, the present invention is not solimited. For instance, the reflective grooves 215 a and 215 b may alsohave arc-shaped sections or rectangular-shaped sections.

As shown in FIG. 10, the reflective surface 215 of the light guidemembers 210A and 210B according to an embodiment may be formed with fastand second reflective grooves 215 a and 215 b, which are symmetricallyformed while being inclined along the widths of light guide members 210Aand 210B. According to the an embodiment, the first and secondreflective grooves 215 a and 215 b may cross each other on thereflective surface 215.

With the above configuration, the light irradiated from the light source200 can be guided toward the exit surface 217 of the light guide members210A and 210B while being diffused in the lateral direction by the firstand second reflective grooves 215 a and 215 b, so that the light can beuniformly distributed in the width direction of the light guide members210A and 210B when the light is received through the incident surfaces211 at longitudinal end portions of the light guide members 210A and210B. As can be understood from the above, the amount of light diffusedin the width direction of the light guide members 210A and 210B mayincrease proportionally to the inclination angle of the first and secondreflective grooves 215 a and 215 b.

FIG. 11 is a graph of light distribution curve on across the width of amanuscript board 51 when the light is illuminated with the light guidemembers 210A and 210B having the first and second reflective grooves 215a and 215 b, which are symmetrically patterned while being non-parallelwith respect to each other, and when the light irradiated from thelongitudinal end portions of the light guide members 210A and 210B isemitted through the exit surface 217.

Comparing the light distributions illustrated in FIG. 11 with thedistribution of FIG. 3, the light guide member 210A or 210B having thefirst and second reflective grooves 215 a and 215 b, which extendnon-parallel with respect to each other and in relation to the width ofthe reflective surface 215, and which can effectively diffuse or scatterthe light in the width direction of the light guide member 210A and210B, results in a more uniform light distribution across the manuscriptboard 51 than the conventional light guide member 1 shown in FIG. 1having a plurality of reflective grooves 1 d, which are formed parallelto each other.

Although the above embodiment has been described as an illustrativeexample with the reflective surface 215 formed with plural reflectivegrooves 215 a and 215 b to allow the light to be subject to scatteredreflections, the present invention is not so limited. For instance, thereflective surface 215 may be provided with a micro-lens shape or acylindrical shape. When the reflective surface 215 has the aboveconfiguration, the reflective surface 215 can scatter the incidentlight, so that the light can be uniformly output through the exitsurface 217. In an embodiment, a light diffusion material, such as awhite pigment, can be coated on the reflective surface 215 such thatlight can be uniformly irradiated from the exit surface 217.

Referring again to FIG. 5, the guide surface 213 is formed on both sidesof the light guide members 210A and 210 b in order to guide the incidentlight, which is incident into the incident surface 211, such that theincident light can be irradiated through substantially the entire areaof the exit surface 217 by internal total reflection.

As shown in FIG. 12, a plurality of guide surfaces 213 are symmetricallyformed at both sides of the light guide members 210A and 210 b toreflect the light, which is reflected from the reflective surface 215 atvarious reflection angles, toward the exit surface of the light guidemembers 210A and 210 b. If the plural guide surfaces 213 aresymmetrically formed on both sides of the light guide members 210A and210 b, most of the light reflected from the reflective surface 215 maybe guided toward the exit surface 217 of the light guide members 210Aand 210 b while being reflected by the guide surfaces 213, so that theamount of light leaked out of the light guide members 210A and 210 bthrough the guide surfaces 213 can be reduced. As the light reflectedfrom the reflective surface 215 is reflected again by the guide surfaces213, the guide surfaces 213 may serve as a virtual light source togetherwith the reflective surface 215. Therefore, the light distribution onthe surface of the manuscript can be adjusted by properly adjusting theangle of guide surfaces 213 when the light is irradiated through theexit surface 217 of the light guide members 210A and 210 b.

According to an embodiment of the present invention, the guide surfaces213 may include a first guide surface 213 a, which extends from bothsides of the reflective surface 215 while forming an obtuse anglerelative to the reflective surface 215, and a second guide surface 213b, which extends from the first guide surface 213 a while forming anobtuse angle relative to the first guide surface 213 a.

If the first and second guide surfaces 213 a and 213 b are formed onboth sides of the light guide members 210A and 210 b, the lightreflected from the reflective surface 215 at a relatively largereflection angle can be reflected toward the exit surface 217 of thelight guide members 210A and 210 b by the first guide surface 213 a, andthe light reflected from the reflective surface 215 at a relativelysmall reflection angle can be reflected toward the exit surface 217 ofthe light guide members 210A and 210 b by the second guide surface 213b, so that the amount of light leaked out of the light guide members210A and 210 b can be reduced.

In order to minimize the light loss, the incident angle of the lightincident onto the first and second guide surfaces 213 a and 213 b fromthe reflective surface 215 is desirably greater than a critical incidentangle θ2 that ensures total reflection of the light.

In accordance with an embodiment, preferably, the angle between thereflective surface 215 and the first guide surface 213 a is equal to orgreater than the sum of the critical incident angle θ2 that ensurestotal reflection of the light and an angle of 90°. In addition, theangle between the first guide surface 213 a and the second guide surface213 b may also be designed such that the incident angle of the light,which is incident onto the second guide surface 213 b from thereflective surface 215, may be equal to or greater than the criticalincident angle θ2. Since the minimum incident angle of the lightincident on the second guide surface 213 b may correspond to an anglebetween a virtual line L (shown in FIG. 12) and the second guide surface213 b of one side of the light guide member 210A or 210B where thevirtual line L extends from the edge serving as the boundary between thereflective surface 215 and the first guide surface 213 a on the otherside of the light guide member 210A or 210B to an edge serving as aboundary between the first guide surface 213 a and the second guidesurface 213 b of the same side of the light guide member 210A or 210B,the angle between the virtual line L and the second guide surface 213 bmay preferably be equal to or greater than the sum of the criticalincident angle θ2 and an angle of 90°.

As described above, according to an embodiment, the light guide members210A and 210B may be formed with polymethyl methacrylate, the criticalincident angle θ2 of which may be 41.8°. Therefore, the angle betweenthe reflective surface 215 and the first guide surface 213 a and theangle between the virtual line L and the second guide surface 213 b matbe made to be equal to or greater than 131.8°.

According to an embodiment of the present invention, although the anglebetween the reflective surface 215 and the first guide surface 213 a,and the angle between the virtual line L and the second guide surface213 b, are both described as being equal to or greater than θ2 plus 90°,since the light may be subject to Lambertian reflection at thereflective surface 215, the amount of light incident on the first guidesurface 213 a may be relatively small. Thus, according to anotherembodiment, the scattering reflection and the uniform light distributionmay be achieved by setting only the angle between the virtual line L andthe second guide surface 213 b greater than the sum of the criticalincident angle θ2 and an angle of 90°.

According to an embodiment, the light guide members 210A and 210B may beformed with material other than polymethyl methacrylate. For instance,the light guide members 210A and 210B may alternatively formed withcolorless transparent resin. The critical incident angle according tothe type of resins can be calculated using Snell's law.

FIG. 13 is a block diagram of the image scanning apparatus according anembodiment of the present invention. Referring to FIG. 13, the imagescanning apparatus according to this embodiment may include the scannermodule 10 e and an image processing unit 20 which processes the imageobtained from the scanner module 10. The image scanning apparatus of thepresent invention may include an MFP (multi-function printer), a copymachine, a facsimile machine, a scanner, or the like.

As various scanner module 10 has already been and will further bedescribed herein. The image processing unit 20 may include at least oneof a file forming unit 21 for forming an image file based on the imageobtained from the image sensor of the scanner module 10 and an imageforming unit 25 for forming an image on a printing medium based on theimage obtained from the image sensor. The file forming unit 21 may be amicroprocessor, microcontroller or the like, that includes a CPU toexecute one or more computer instructions to implement the operation offorming the image files from the image data received from the imagesensor of the scanner module 10, and may further include a memorydevice, e.g., a Random Access Memory (RAM), Read-Only-Memory (ROM), aflesh memory, or the like, to store the one or more computerinstructions. The image forming unit may include any of various printingmechanisms, e.g., one utilizing electro-photographic image formingtechnique, which may include photosensitive member to which latentimages are formed, and the latent image of which is developed into atoner image that is transferred and fixed on a printing medium, e.g., asheet of paper, one that utilizes ink jet technique including an ink jetprint head that places tiny ink droplets through nozzles of the printhead directly on the paper, or the like.

Accordingly, if the image scanning apparatus employs the scanner module10 having the illumination device 100 described above, the image sensorsaligned in a plurality of rows can output uniform values even if theposition of optical elements, such as reflection mirrors, becomes out ofalignment by various external parameters.

Although some of the embodiments, such as sown in FIG. 6, are describedto include the separate light guide members 210A and 210B that areinstalled together through the holder 230, the present invention is notso limited. For instance, according to an alternative embodiment, e.g.,as shown in FIG. 14, a pair of light guide members 310A and 310B may beextruded as an integral body, e.g., by using a single mold.

FIG. 14 illustrates a structure in which a first light guiding member310A and a second light guiding member 310B may be connected at oppositeends thereof. As shown, the first light guiding member 310A and thesecond light guiding member 310A are extruded as an integrally formedbody or from the same single mold, e.g., through an injection moldingprocess, and are assembled together. The light source, which irradiateslight toward the light guide members 310A and 310B, may also beintegrally formed with a single substrate 360. In addition, as shown inFIG. 15, a coupling structure 370 may be provided between the lightsource substrate 360 and the light guide members 310A and 310B toimprove assembling process for the illumination device 100. Thisextrusion and simultaneous assembly as described above may help tofurther alleviate the problem of assembling tolerance, simplifyassembling work, and decrease production costs.

Although the first and second guide surfaces 213 a and 213 b are shownin FIG. 12 as having linear cross-sectional shapes, the presentinvention is not so limited. For instance, according to an alternativeembodiment, as, e.g., illustrated in FIG. 16, a first guide surface 413a of light guide member 410A and/or 410B may have a curved shape and asecond guide surface 413 b of the light guide members 410A and 410B mayhave a linear sectional shape.

Referring to FIG. 5, while in that figure the scattered reflection isshown and described to occur only at the reflective surface 215 of thelight guide members 210A and 210B. However, the present invention is notso limited. For instance, according to another embodiment, as, e.g.,shown in FIG. 17, a reflective member 535 is formed on at least one of areflective surface 515 and a guide surface 513 of light guide members510A and 510B. Referring to FIG. 17, the reflective member 535 is formedon the guide surface 513 and the reflective surface 515, respectively.The reflective member 535 may be obtained by forming the reflectivegroove structure on the guide surface 513 or the reflective surface 515as previously described, or, for example, by coating or printing theguide surface 513 or the reflective surface 515 with a material havinghigh reflectivity of about 90% or more in the wavelength band of thelight irradiated from the light source 500. Such material having highreflectivity is generally known in the art, and thus is no described indetailed herein for the sake of brevity.

In addition, although FIG. 5 shows the exit surface 217 in the form ofthe convex lens having an arcuate shape, the present invention is not solimited. For instance, as shown in FIG. 17, the exit surface may beprepared in the form of a flat lens having a plane shape or a Fresnellens pattern.

Although FIG. 7 shows the incident surface 211 formed at bothlongitudinal end portions of the light guide members 210A and 210B, thepresent invention is not so limited. For instance, according to anembodiment, as shown, e.g., in FIG. 18, a light source 600 may beinstalled only at one longitudinal end portion of light guide members610A and/or 610B, so that only one incident surface 611 may be formed onone longitudinal end portion of light guide members 610A and/or 610B. Inthis case, a reflective plate 631 may be provided at the otherlongitudinal end portion of light guide members 610A and/or 610B. Thus,the light incident through the incident surface 611 or the reflectivesurface 615 is reflected into the light guide members 610A and 610B,thereby preventing the light irradiated from the light source 600 frombeing output through other surfaces.

In addition, although FIG. 10 shows the first and second reflectivegrooves 215 a and 215 b that cross each other as one possibleillustrative pattern thereof, the present invention is not so limited.For instance, according to an embodiment as shown, e.g., in FIG. 19,first and second reflective grooves 711 a and 711 b of a reflectivesurface 711 may be patterned not to cross each other, but arealternately arranged along the light guide members 710A and 710B,achieving the same beneficial aspects contemplated by the presentdisclosure.

While according to the embodiment thus far described, the first andsecond reflective grooves 215 a and 215 b are described to have the sameinclination angle across the length of the light guide members. However,the present invention is not so limited. The light distribution on thesurface of the manuscript may not be uniform in the width direction ofthe light guide members 210A and 210B at the vicinity of thelongitudinal end portions of the light guide members 210A and 210B.Thus, according to an alternative embodiment, as shown, e.g., in FIG.20, the inclination angle of first and second reflective grooves 811 aand 811 b formed in a reflective surface 811 may gradually increase fromthe center towards the ends of light guide members 810A and 810B. Inthis case, light can be effectively diffused even at the end portions ofthe light guide members 810A and 810B.

In addition, the amount of light radiated from the both longitudinalends of the light guide members 810A and 810B may increaseproportionally to the inclination angle of the first and secondreflective grooves 811 a and 811 b formed in the light guide members810A and 810B. Therefore, if the inclination angle of the first andsecond reflective grooves 811 a and 811 b is gradually increased fromthe center towards the ends of light guide members 810A and 810B asdescribed above, the amount of light irradiated onto the object 55 fromthe both longitudinal ends of the light guide members 810A and 810B mayincrease. Thus, there may be a difference between the amount of lightirradiated onto the object 55 from the center of the light guide members810A and 810B and the amount of light irradiated onto the object 55 fromthe both longitudinal ends of the light guide members 810A and 810B.

In order to address the above difference, according to anotherembodiment of the present invention, as shown, e.g., in FIG. 21, theinclination angle of the first and second reflective grooves 911 a and911 b gradually increases from the center to the both ends of lightguide members 910A and 910B, and at the same time, the interval betweenthe first and second reflective grooves 911 a and 911 b increasesproportionally to the inclination angle of the first and secondreflective grooves 911 a and 911 b. In this case, the amount of lightradiated onto the object from the both longitudinal ends of the lightguide members 910A and 910B may be reduced, so the difference betweenthe amount of light irradiated onto the object 55 from the center of thelight guide members 910A and 910B and the amount of light irradiatedonto the object 55 from the both longitudinal ends of the light guidemembers 910A and 910B can be reduced.

While various embodiments have been described in relation to a CCDM, inwhich the light source and the plural reflection mirrors are integratedin a single module, the present invention can also be applied to an MMT(mirror moving type), in which one light source and one reflectionmirror are integrated in a single module and two reflection mirrors areintegrated in another single module such that the modules including themirrors can read the image while moving along the object.

Although few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

Finally, it is the applicant's intent that only claims that include theexpress language “means for” or “step for” be interpreted under 35U.S.C. §112, paragraph 6. Claims that do not expressly include thephrase “means for” or “step for” are not to be interpreted under 35U.S.C. §112, paragraph 6.

1. A scanner module, comprising: a light source configured to generatelight; and a light guide member configured to receive the light from thelight source, and to direct the received light toward a document to bescanned, the light guide member having a length and a width, the lightsource being disposed on at least one longitudinal end of the lightguide member, wherein the light guide member has a reflective surfacefacing the document to be scanned, the reflective surface having formedthereon one or more first reflective grooves and one or more secondreflective grooves, at least one of the one or more first reflectivegrooves and at least one of the one or more second reflective groovesbeing not parallel with respect to each other, and wherein the firstreflective grooves and the second reflective grooves are inclined withrespect to the width direction of the light guide member.
 2. The scannermodule according to claim 1, wherein the at least one of the one or morefirst reflective grooves and the at least one of the one or more secondreflective grooves cross each other.
 3. The scanner module according toclaim 1, wherein the first and second reflective grooves are provided inan alternating manner along the length of the light guide member.
 4. Thescanner module according to claim 1, wherein each of the one or morefirst reflective grooves and the one or more second reflective groovesis inclined at a corresponding one of one or more incline angles withrespect to a center line extending across the width of the light guidemember, the center line dividing the reflective surface into two equalhalves, and wherein the one or more incline angles become progressivelylarger as moving from the center line towards a longitudinal end of thelight guide member.
 5. The scanner module according to claim 4, whereinintervals between neighboring ones of the one or more first reflectivegrooves and the one or more second reflective grooves increaseprogressively as moving from the center line towards a longitudinal endof the light guide member proportionally to increase in the one or moreincline angles.
 6. The scanner module according to claim 1, wherein thelight source comprises a light emitting diode.
 7. The scanner moduleaccording to claim 6, wherein the light guide member comprises a pair oflight guide members disposed adjacent to each other non-parallel to eachother such that both facing the document to be scanned.
 8. The scannermodule according to claim 7, wherein each light guide member of the pairof light guide members comprises a first incident surface at a firstlongitudinal end and a second incident surface at a second longitudinalend opposite the first longitudinal end, and wherein the light emittingdiode comprises a first pair of light emitting diodes fabricated on afirst common substrate and a second pair of light emitting diodesfabricated on a second common substrate, the first pair of lightemitting diodes being disposed adjacent the first incident surface ofboth light guide members of the pair of light guide members, the secondpair of light emitting diodes being disposed adjacent the secondincident surface of both light guide members of the pair of light guidemembers.
 9. The scanner module according to claim 6, wherein the lightemitting diode generates light having a wavelength band of three primarycolors including red, green and blue colors.
 10. The scanner moduleaccording to claim 6, wherein the light emitting diode comprises a whitelight emitting diode that generates a white color, the while lightemitting diode being a blue light emitting diode coated with afluorescent material.
 11. The scanner module according to claim 1,wherein each of the one or more first reflective grooves and the one ormore second reflective grooves has a triangular cross-sectional shape.12. The scanner module according to claim 1, wherein each of the one ormore first reflective grooves and the one or more second reflectivegrooves has an arcuate cross-sectional shape.
 13. An image scanningapparatus, comprising: a scanner module configured to convert a visualimage information of a document into an electric signal, the scannermodule comprising: a light source configured to generate light; a lightguide member configured to receive the light from the light source, andto direct the received light toward the document to be scanned, thelight guide member having a length and a width, the light source beingdisposed on at least one longitudinal end of the light guide member, thelight guide member having a reflective surface facing the document to bescanned, the reflective surface having formed thereon one or more firstreflective grooves and one or more second reflective grooves, at leastone of the one or more first reflective grooves and at least one of theone or more second reflective grooves being not parallel with respect toeach other, wherein the first reflective grooves and the secondreflective grooves are inclined with respect to the width direction ofthe light guide member; an image sensor configured to receive areflected light reflected off the document, and to produce image signalbased on the received reflected light; and an image processing unithaving an input through which to receive the image signal from the imagesensor, the image processing unit being configured to produce a datapattern based on the received image signal, the data pattern beingrepresentative of the visual image information.
 14. The image scanningapparatus according to claim 13, wherein the scanning module furthercomprises: one or more reflecting mirrors disposed in an optical pathbetween the document to be scanned and the image sensor, the one or morereflecting mirrors being configured to direct the reflected light offthe document toward the image sensor; and a focusing lens disposedbetween the one or more reflecting mirrors and the image sensor to focusthe reflected light redirected by the one or more reflecting mirrors onthe image sensor.
 15. The image scanning apparatus according to claim13, wherein each of the one or more first reflective grooves and the oneor more second reflective grooves being inclined at a corresponding oneof one or more incline angles with respect to a center line extendingacross the width of the light guide member, the center line dividing thereflective surface into two equal halves, and wherein the one or moreincline angles become progressively larger as moving from the centerline towards a longitudinal end of the light guide member.
 16. The imagescanning apparatus according to claim 15, wherein intervals betweenneighboring ones of the one or more first reflective grooves and the oneor more second reflective grooves increase progressively as moving fromthe center line towards a longitudinal end of the light guide memberproportionally to increase in the one or more incline angles.
 17. Theimage scanning apparatus according to claim 13, wherein the light sourcecomprises a light emitting diode.
 18. The image scanning apparatusaccording to claim 17, wherein the light guide member comprises a pairof light guide members disposed adjacent to each other non-parallel toeach other such that both facing the document to be scanned, whereineach light guide member of the pair of light guide members comprises afirst incident surface at a first longitudinal end and a second incidentsurface at a second longitudinal end opposite the first longitudinalend, and wherein the light emitting diode comprises a first pair oflight emitting diodes fabricated on a first common substrate and asecond pair of light emitting diodes fabricated on a second commonsubstrate, the first pair of light emitting diodes being disposedadjacent the first incident surface of both light guide members of thepair of light guide members, the second pair of light emitting diodesbeing disposed adjacent the second incident surface of both light guidemembers of the pair of light guide members.
 19. The image scanningapparatus according to claim 17, wherein the light emitting diodegenerates light having a wavelength band of three primary colorsincluding red, green and blue colors.
 20. The image scanning apparatusaccording to claim 17, wherein the light emitting diode comprises awhite light emitting diode that generates a white color, the while lightemitting diode being a blue light emitting diode coated with afluorescent material.
 21. The image scanning apparatus according toclaim 13, wherein each of the one or more first reflective grooves andthe one or more second reflective grooves has a triangularcross-sectional shape.
 22. A light guide member having a length and awidth for use in an image scanning apparatus for reading a visual imageof a document, comprising: one or more incident surfaces configured toreceive light from a point light source, the one or more incident lightsurface being provided at least one longitudinal end of the light guidemember; an exit surface facing the document to be scanned, the exitsurface defining a top surface of, and extending along the length of,the light guide member; a reflective surface disposed at a bottom of thelight guide member, the reflective surface being configured to reflectthe light received through the one or more incident surfaces; and one ormore light guide surfaces extending between the reflective surface andthe exit surface, the one or more light guide surface being configuredto reflect the light reflected by the reflective surface toward the exitsurface, wherein the reflective surface has formed thereon one or morefirst reflective grooves and one or more second reflective grooves, atleast one of the one or more first reflective grooves and at least oneof the one or more second reflective grooves being not parallel withrespect to each other, and wherein the first reflective grooves and thesecond reflective grooves are inclined with respect to the widthdirection of the light guide member.
 23. The light guide memberaccording to claim 22, wherein each of the one or more first reflectivegrooves and the one or more second reflective grooves is inclined at acorresponding one of one or more incline angles with respect to a centerline extending across the width of the light guide member, the centerline dividing the reflective surface into two equal halves, the one ormore incline angles becoming progressively larger as moving from thecenter line towards a longitudinal end of the light guide member. 24.The light guide member according to claim 23, wherein intervals betweenneighboring ones of the one or more first reflective grooves and the oneor more second reflective grooves increase progressively as moving fromthe center line towards a longitudinal end of the light guide memberproportionally to increase in the one or more incline angles.
 25. Thelight guide member according to claim 22, wherein each of the one ormore first reflective grooves and the one or more second reflectivegrooves has a triangular cross-sectional shape.
 26. The light guidemember according to claim 22, wherein the exit surface has an arcuateshape.
 27. The light guide member according to claim 22, wherein theexit surface has a Fresnel lens pattern.
 28. The light guide memberaccording to claim 22, wherein each of the one or more light guidesurfaces comprises a first guide surface and a second guide surface, thefirst guide surface extending between the reflective surface and thesecond guide surface, the second guide surface extending between thefirst guide surface and the exit surface, the reflective surface and thefirst guide surface defining a first obtuse angle therebetween, thefirst guide surface and the second guide surface defining a secondobtuse angle therebetween, and wherein at least one of the first obtuseangle and the second obtuse angle is greater than or equal to a sum of90° and a critical incident angle, the critical incident angle beingdependent on a material with which the light guide member is made, andbeing an angle at which substantially all of light incident isreflected.
 29. The light guide member according to claim 28, wherein thelight guide member is made from polymethyl methacrylate material, thecritical incident angle being 41.8°.